Theory of forces and stresses in spot welded overlap joints

The complete equations describing simple relations between forces and stresses at the weld spot of overlap joints are presented, and applied to specimens used in industry as an example. The equations are also modified in respect to a measuring method for determining the weld spot forces. The essential components of the theoretical description are: an orthogonal reference system at the weld spot positioned according to the principal loading direction, the decomposition of the weld spot forces into joint face forces and >>eigenforces<<, the weld spot modelled as a rigid core for evaluating the stresses connected with the joint face forces, and a homogeneous distribution of the stresses resulting from the >>eigenforces<<. The assumptions and possible complications of the method under engineering aspects and the details of the rigid core model are described in separate publications.